The invention relates to an x-ray examination apparatus comprising a parallelogram type arm whose one end is mounted by a bearing and whose other end bears, via a support-mounting, an x-ray tube with a radiation diaphragm, wherein the parallelogram arm is rotatable about a vertical axis and can be moved in a vertical direction such that the central ray of the x-ray tube retains its direction.
An x-ray examination apparatus of this type is known from the brochure "Nanomobil 2i" of the Siemens firm. This apparatus, which is a mobile x-ray apparatus, is e.g. transported to a patient resting on an examination table for an x-ray photograph. An x-ray cassette is pushed beneath the patient. The parallelogram arm with the x-ray tube is rotated in such a manner that the diaphragmed-in radiation field covers the cassette. When the cassette is brought into another position along the table beneath the patient for an additional photographic exposure, the parallelogram arm must be rotated, and the x-ray tube must be newly adjusted so that the collimated radiation field again coincides with the cassette.